Hamer began his career at Reading and went on to have loan spells at Crawley, Brentford and Exeter.

"Last season we went with an out-and-out number one all season in Frank Fielding and an inexperienced back up with Dave Richards," said Bristol City manager Steve Cotterill.

"You can't do that in the Championship so we've been looking to bring in another good keeper. Even though young Max O'Leary has done fantastically well in pre-season, we needed another experienced one so I'm delighted Ben has agreed to come on board."